JPH06224143A - Processing apparatus and gas shower nozzle - Google Patents

Abstract

PURPOSE:To provide a processing apparatus which is able to blow off impurities such as O2 or the like attached to semiconductor wafers and heat dissipated from them when the semiconductor wafers are loaded into a processing chamber from a loading area so as to restrain impurities from attaching to the semiconductor wafer and a chemical reaction (deposition of natural oxide film) from occurring on the surface of the wafer. CONSTITUTION:A processing apparatus is equipped with a gas shower mechanism 90 provided with a gas shower nozzle 94 which is provided adjacent to an oven inlet 41a and rectilinearly jets out inert gas in a wide and thin laminar flow at a high speed to blow off impurities attached to the wafers 5 and heat released from them when semiconductor wafers 5 housed in a wafer boat 61 are loaded into a processing chamber 41 from a loading area 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus and a gas shower nozzle used in, for example, a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art For example, in a semiconductor process, various processing apparatuses for forming an oxide film on a semiconductor wafer, forming a thin film by a thermal CVD method, and forming a high impurity concentration region by a thermal diffusion method are available. It is used.

As a device applied to these various processing apparatuses, a vertical type heat treatment apparatus has been widely adopted in recent years, instead of a conventional horizontal type. The vertical heat treatment apparatus will be described below as an example.

This vertical heat treatment apparatus has a box-shaped apparatus body in which a processing chamber for performing a predetermined process on a semiconductor wafer as an object to be processed and a loading process for inserting / removing the semiconductor wafer into / from the processing chamber from below. A loading area having a mechanism, an area (I / O area) for loading / unloading a carrier containing a semiconductor wafer into / from the apparatus main body, a transfer stage for temporarily receiving this carrier, and this transfer stage And a transfer machine (wafer transfer) for transferring the semiconductor wafer in the carrier to the loading mechanism in the loading area.

In the processing chamber, a vertically long quartz process container (heating furnace) equipped with a heater is installed so that it can be opened downward. There is a loading area just below this processing chamber, and a wafer boat and a boat elevator as a loading mechanism are installed in this area.

In such a vertical heat treatment apparatus, when a carrier in which a large number of semiconductor wafers are aligned and stored is placed in the loading / unloading area of the apparatus main body, this carrier is placed on a transfer stage by a carrier transfer or the like. The semiconductor wafers in the carriers on the transfer stage are transferred to the wafer boat in the loading area one by one or five by the transfer machine and stored and held in a multistage state. In this state, the wafer boat is raised by the boat elevator to load the semiconductor wafer into the process container, and the process container is sealed and heated while the atmosphere is replaced with a predetermined processing gas atmosphere. Is processed.

The processed semiconductor wafer is lowered from the inside of the process container by the boat elevator together with the wafer boat and pulled out to the loading area directly below, and then returned to the carrier on the transfer stage by the transfer machine. The carrier is taken out from the loading / unloading area to the outside of the apparatus main body, or is transferred to the processing apparatus for the next process connected thereto.

In a processing operation in such a vertical heat treatment apparatus, when a semiconductor wafer is raised together with a wafer boat from a loading area to be inserted into a process container, or when the semiconductor wafer is lowered and pulled out from the process container after the process, in the middle thereof. Since there is a considerably high temperature atmosphere even near the furnace opening, if atmospheric air exists there, there is a problem that a natural oxide film is formed on the surface of the semiconductor wafer by O ₂ in the atmospheric air. Therefore, in order to perform such loading / unloading in an inert gas atmosphere (non-oxygen atmosphere) such as N ₂ gas, a gas is used as a closed system structure in which the loading area is separated from the atmosphere in the main body of the apparatus. It is desired to replace / maintain the atmosphere with N ₂ gas by supplying / discharging means.

Moreover, the gas atmosphere in the apparatus main body must be kept at a positive pressure at all times to prevent the invasion of the atmosphere from the outside, and the gas atmosphere in the apparatus main body is kept to repeat the semiconductor wafer processing operation. Gaseous impurities such as carbon are generated in the surface, or particulate impurities (particles) such as oil mist and dust are generated, and these impurities adhere to the semiconductor wafer or cause a chemical reaction (chemical contamination), resulting in a semiconductor element. Therefore, it is necessary to always introduce a clean inert gas as a purge gas into the main body of the device to maintain the inert gas atmosphere in the main body at a positive pressure and high purity. Is desired.

[0010]

However, even in the case of the vertical heat treatment apparatus having the closed system structure as described above, it is difficult to maintain the inert gas atmosphere in the apparatus main body, particularly the loading area, at high purity. When semiconductor wafers are held on the wafer boards in multiple stages from the loading area and are inserted / unloaded (loaded / unloaded) into / from the process container, gaseous impurities such as O ₂ and particulate impurities (particles) are interleaved between the semiconductor wafers. ) Is present, or hot air is involved, the impurities may adhere to the semiconductor wafer or cause a chemical reaction (natural oxide film generation, etc.), which may cause defects and deteriorate the characteristics and yield of semiconductor elements. There's a problem.

The present invention has been made in view of the above circumstances, and when an object to be processed is inserted into and removed from a loading area (loading / unloading), the object to be processed is near the insertion / removal opening of the processing chamber. Impurities such as attached O ₂ and heat are expelled so as to be blown away, which is extremely useful for suppressing adhesion of impurities to the object to be processed and chemical reaction (generation of natural oxide film, etc.). An object is to provide a processing device.

Further, according to the present invention, when an object to be processed is inserted into or removed from (loading / unloading) the processing area from the loading area, impurities such as O ₂ attached to the object to be processed and heat are expelled. In addition, it is an object of the present invention to provide a very effective gas shower nozzle.

[0013]

In order to achieve the above object, the processing apparatus according to the present invention has a loading mechanism for inserting and removing the object to be processed into and from a processing chamber for performing a predetermined processing on the object. A processing apparatus having a loading area in which the loading area is set to an inert atmosphere and an object to be processed is inserted into and removed from the processing chamber by a loading mechanism from the loading area,
A gas shower mechanism for injecting an inert gas at a high wind speed to blow away impurities and heat attached to the object to be processed is provided near the object insertion / extraction opening in the processing chamber.

As a result, when the object to be processed is inserted into or removed from the processing area (loading / unloading),
An inert gas is jetted from the gas shower mechanism at a high wind speed in the vicinity of the workpiece insertion / extraction opening in the processing chamber, and impurities such as O ₂ and heat attached to the workpiece can be expelled so as to be expelled. It is very useful for suppressing the adhesion of impurities to the processed material and the chemical reaction (generation of natural oxide film etc.).

The gas shower mechanism is provided with a gas introduction pipe for introducing an inert gas and a gas shower nozzle connected to the tip of the gas shower pipe. The inert gas is discharged from the gas shower nozzle by the loading mechanism. In the vertical heat treatment apparatus, a large number of semiconductor wafers are loaded in a wafer boat in a direction that is orthogonal to the insertion / removal direction and that is configured to inject straightly into a wide thin film over substantially the entire width of the object to be processed. When holding horizontally in multiple stages and inserting / removing into / from the process container,
It becomes possible to reliably blow off gaseous impurities such as O ₂ and particulate impurities (particles) existing between the respective semiconductor wafers, and to prevent the entrainment of heat.

The gas shower nozzle according to the present invention has a long, wide, and thin hollow flat box-shaped nozzle body having a gas inlet pipe connection port at the base end and a gas shower outlet at the tip. Plural kinds of hindrances that are arranged in order from the base end side in the nozzle body and stepwise equalize the pressure distribution while diffusing and changing the gas flow entering from the gas introduction pipe connection port in the width direction of the nozzle body. Plate and a plurality of straightening vanes that are arranged in parallel from the final baffle plate in the nozzle body to the tip outlet, and the gas flow is accelerated in the long landing section between these straightening vanes to blow the tip. It is characterized in that it is configured to blow out straightly in a thin film shape wider than the mouth.

By using this gas shower nozzle in the gas shower mechanism of the above-mentioned processing apparatus, gaseous impurities such as O ₂ and particulate impurities (particles) can be generated between a large number of semiconductor wafers held in multiple stages. The blowout and the prevention of entrapment of heat become more reliable.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a processing apparatus and a gas shower nozzle according to the present invention will be described below with reference to the drawings. An example in which this processing apparatus is applied to a vertical heat treatment apparatus is shown.

First, FIG. 1 is a vertical sectional view showing the structure of a vertical heat treatment apparatus according to this embodiment, FIG. 2 is a vertical sectional view taken along the line A--A of FIG. 1, and FIG. 3 is a horizontal sectional view of the apparatus. , FIG. 4 is B of FIG.
-B is a sectional view taken along line B, and FIG. 5 is a schematic view showing a control system. This vertical heat treatment apparatus is used as an oxidation apparatus or a CVD apparatus for forming an insulating film on a semiconductor wafer as an object to be processed.

As shown in FIGS. 1 to 3, the vertical heat treatment apparatus according to this embodiment has an apparatus body 1. The apparatus main body 1 has a large box-like structure having a width dimension of about 1 meter, a depth dimension of about 2 meters, and a height of about 3 meters using a housing panel 1a, and the front portion thereof faces a clean room 2 in a factory. No, most of the rest is installed in a maintenance room 4 separated by a partition 3.

A processing chamber 10 for performing a predetermined process on a thin disk-shaped semiconductor wafer 5 as an object to be processed is partitioned by partition walls 11 and 12 in a substantially upper rear part of the apparatus main body 1. The loading area 13 is partitioned just below the processing chamber 10 by the partition walls 12 and 14 so as to be airtight, and a plurality of semiconductor wafers 5, for example, 25 semiconductor wafers 5 are arranged in parallel in the front half of the apparatus main body 1. A loading / unloading area (I / O area) 15 for the carrier 6 stored and held in a state is partitioned from the processing chamber 10 and the loading area 13 by partition walls 11 and 14.

A small pass box 16 having airtightness is supported by a stand 17 at an appropriate height so as to be fitted in a part of a partition wall 14 that partitions the loading / unloading area 15 and the loading area 13. Transfer stages 18 are arranged in two upper and lower stages in the pass box 16,
The carriers 6 can be received one by one on their respective upper surfaces.

To describe the details of the respective parts, first, in order to carry in the carrier 6 accommodating a plurality of semiconductor wafers 5 into the carry-in / carry-out area 15 and vice versa on the front panel of the apparatus main body 1. The front door 20 is provided so as to automatically open and close vertically.

In the loading / unloading area 15 inside thereof, two posture changing mechanisms 21 as I / O ports on which the carriers 6 can be mounted are arranged on the left and right. The posture changing mechanism 21 functions to turn the carrier 6 placed on the upper surface in the upward state (the state in which the semiconductor wafer 5 is held upright) 90 degrees to be turned sideways, or conversely, to change the sideways state to the upward direction. It is a structure that makes up.

In the loading / unloading area 15, a carrier transfer 22 is provided at a position just behind the posture changing mechanism 21.
Is installed so that it can be moved up and down via an elevator 23, and a carrier stock stage 24 is provided above the pass box 16 on the rear side thereof. It has a plurality of shelves 24a capable of storing the carriers 6 conveyed by the carrier transfer 22 from the posture changing mechanism 21 in two rows and four stages while keeping them in a horizontal orientation.

The atmosphere in the loading / unloading area 15 is atmospheric air, but in order to remove adhered dust such as particles (fine particles) on the main surface of the semiconductor wafer 5 in each carrier 6 with clean air as much as possible. First, between the back surface of the carrier stock stage 24 and the partition wall 11 in the loading / unloading area 15, a vertically long first filter unit 25 having a filter and a fan is installed.
The first filter unit 25 has a clean air suction port 25a at the upper end that opens to the top plate portion of the apparatus main body 1, and sucks clean air in the maintenance room 4 from here to clean the carrier stock through the filter. The side flow can be performed toward the semiconductor wafer 5 in the horizontal state in the carrier 6 of the stage 24. A current plate 26 having a large number of holes formed therein is provided vertically on the front side of the carrier stock stage 24 to assist the side flow.

A second filter unit 27 having a built-in filter and fan is provided near the lower end of the straightening plate 26 on the front side.
Is installed, and while the clean air coming from the first filter unit 25 through the straightening vane 26 is cleaned again, the carrier 6 on the left and right posture changing mechanisms 21 below is cleaned.
Downflow can be performed toward the semiconductor wafer 5 in the vertical state.

Further, the floor plate of the apparatus body 1 which is directly below it is provided with a drainage-like suction port 28 so that the clean air downstream from the second filter unit 27 is discharged to the maintenance room 4 outside the apparatus body 1. It is supposed to do.

The pass box 16 in which the transfer stages 18 are arranged in upper and lower two stages is a small (small capacity) vertically elongated box shape,
The side surface of the loading / unloading area 15 and the loading area 13
Auto doors 31 and 32 are provided on the side and the side, respectively.
Each of the automatic doors 31 and 32 has its own opening / closing drive unit, and can open / close alternately to communicate / block the loading / unloading area 15 and the loading area 13. When the automatic door 31 on the loading / unloading area 15 side is opened, the carriers 6 are loaded one by one on the upper and lower two transfer stages 18 by the carrier transfer 22 or vice versa.

On the other hand, a vertical process container 41 is installed in the processing chamber 10. The process container 41 is a heating furnace called a process tube formed of, for example, quartz, and has an inverted U-shaped cross section, that is, a vertical substantially cylindrical shape with an upper end closed. A heater 42 is provided so as to surround the outer periphery of the process container 41, and a protective cover 43 in which a cooling pipe, a heat insulating material and the like are incorporated is further provided around the heater 42.
Is covered.

A manifold 44 is connected to the lower end of the opening of the process container 41. The manifold 44 is in the shape of a rectangular cylinder with upper and lower flanges. As shown in FIG. 1, an exhaust pipe 45 with an automatic damper 45a for exhausting the gas in the process container 41 is connected to the peripheral wall portion, and the tip of the exhaust pipe 45 is attached. It is led out of the apparatus main body 1 and connected to a factory exhaust device 46 (see FIG. 5). Further, a gas introduction pipe 56 for introducing new gas into the process container 41 via the manifold 44 is provided. A tip of the gas introduction pipe 56 is led out of the apparatus main body 1, and is connected to a predetermined process gas (processing gas) supply device 48 and an inert gas device 49 via an automatic switching valve 47 as shown in FIG. A process gas and an inert gas (for example, N ₂ gas in this embodiment) are alternately supplied to the process container 4
It can be introduced in 1.

Further, around the manifold 44 under the process container 41, an annular chamber-shaped scavenger 51 is constituted by the partition wall 12 and a square dish-shaped case 51a fixed to the lower surface thereof, and inside the scavenger 51. A heat exhaust pipe 52 that constantly discharges heat and unnecessary gas accumulated around the lower part of the process container 41 is led out, and its tip is led out of the apparatus main body 1 and connected to a factory exhaust device 46 (see FIG. 5). . A branch pipe 54 with an automatic damper 54 a is provided in the process chamber 10 in the middle of the heat exhaust pipe 52.

The case 5 of the scavenger 51
A central portion of the bottom surface of 1a is opened so as to communicate with the lower end of the manifold 44, and a furnace opening 41a is formed as an insertion / removal opening for the semiconductor wafer (object to be processed) 5 into / from the process container 41. An automatic shutter 55 is installed in the loading area 13 to close the furnace opening 41a from the lower surface side in an airtight state via an O-ring. The automatic shutter 55 opens and closes the furnace opening 41a by moving up and down and rotating in the lateral direction by the opening and closing drive section 55a.

A wafer boat 61 and a boat elevator 62 are installed in the loading area 13 as a loading mechanism for inserting / removing the semiconductor wafer 5 into / from the process container 41 of the processing chamber 10. The wafer boat 61 is made of quartz and is vertically long and has a structure in which a large number of semiconductor wafers 5 are housed and held in multiple stages in a horizontal state with vertical intervals.

The wafer boat 61 is vertically supported by a boat elevator 62 just below the furnace opening 41a of the process vessel 41. This wafer boat 61
With a large number of semiconductor wafers 5 housed therein, the boat elevator 62 raises and inserts it into the process container 41 with the opening of the shutter 55, or conversely lowers and pulls out from the process container 41. To do. It should be noted that the wafer boat 61 is raised and the process container 41 is raised.
When inserted into the inside of the process vessel 41, the flange 61a at the bottom of the wafer boat 61 closes the furnace opening 41a instead of the automatic shutter 55, so that the inside of the process container 41 can be sealed.

Further, a transfer machine (wafer transfer) 63 is installed between the wafer boat 61 and the pass box 16 in the loading area 13 so as to be lifted and lowered by a transfer elevator 64. While the transfer machine 63 moves up and down, the semiconductor wafers 5 in the carrier 6 on the upper and lower transfer stages 18 in the pass box 16 are taken out one by one and stored in the wafer boat 61 in the loading area 13. Hold or vice versa
It functions to return the semiconductor wafer 5 from 1 into the carrier 6 on the transfer stage 18.

In order to replace / maintain the inside of the loading area 13 defined by the partitions 12 and 14 in the apparatus main body 1 with a positive pressure inert gas atmosphere, a gas introduction pipe 71 as a first gas supply / discharge means. And an exhaust pipe 72.

The gas introduction pipe 71 is connected to the primary side (suction side) of the blower fan 82 in the middle of the gas circulation path 81 installed under the floor of the apparatus body 1 as a gas circulation cooling and purification system described later. There is. This gas introduction pipe 7
1 is led out of the apparatus main body 1 and is connected to an inert gas supply device 49 via a flow rate adjusting valve 73 and a regulator 74 as shown in FIG. 5, and N ₂ gas as an inert gas is passed through the gas circulation path 81. It can be introduced into the loading area 13. The exhaust pipe 72 is led out from the downstream side in the loading area 13, has an automatic damper 72a on the way, and is connected to the above-mentioned factory exhaust device 46.

At the time of initial replacement in the loading area 13, the auto-damper 72a is opened, the factory exhaust device 46 exhausts the loading area 13, and N ₂ gas is introduced at about 200 to 400 liters / min. In the steady state after the replacement, the N ₂ gas introduction amount is set to 50
Throttle to about 1 / min, the auto-damper 72a of the exhaust pipe 72 is closed, and the loading area 1 is closed by exhausting the clearance in the loading area 13 or the pressure adjusting damper.
The inside of 3 is maintained in an atmosphere of N ₂ gas having an appropriate positive pressure. In addition, the leak gas due to the clearance exhaust is the auto damper 54 of the heat exhaust pipe 52 of the scavenger 51.
Factory exhaust from the branch pipe 54 with a.

The gas circulation cooling and purification system maintains the N ₂ gas atmosphere in the loading area 13 at a high purity and prevents an abnormal temperature rise even when the semiconductor wafer 5 is repeatedly processed. In this system configuration, first, a N2 gas in the loading area 13 is first taken out of the system, and a gas circulation path 81 for purifying and cooling the N ₂ gas and then recirculating it back into the loading area 13 is provided under the floor of the apparatus main body 1. , A blower 82 is installed in the middle of this, and a chemical filter 83 as a gas filter is installed on the secondary side of the blower 82,
Further, a gas cooler 84 is installed on the secondary side thereof. The chemical filter 83 is a gas purifier in which a metal getter such as zirconia that absorbs gaseous impurities (moisture, oxygen, hydrocarbons, etc.) is replaceably incorporated according to the application. Further, the gas cooler 84 is a radiator type in which radiating fins are provided on a water-permeable cooling pipe, and has a cooling capacity such that the secondary side blown-out gas temperature becomes 50 ° C. or lower.

A particle filter 85 as a gas filter that receives the N ₂ gas from the gas circulation path 81 and blows it into the loading area 13 is provided on one side surface of the loading area 13. This particle filter 85 is a vertical type ULPA.
Grade absolute filter with filtering trapping particulate impurities N ₂ gas (particle such as dust), blow out the N ₂ gas from the one side in the loading area 13 in a horizontal laminar flow state. Further, in order to make the horizontal laminar flow state of the N ₂ gas more reliable, a straightening plate 86 having a large number of holes on the other side surface in the loading area 13 is vertically provided so as to face the filter 85. , Through this straightening plate 86 to the N ₂
The gas is sucked and conducted to the gas circulation path 81.

Here, in the upper part of the loading area 13, when the semiconductor wafer 5 is loaded / unloaded into / from the process container 41 from the loading area 13 by the loading mechanism, the object to be processed of the process container 41 is loaded. A gas shower mechanism 90 for injecting an inert gas at a high wind speed to blow out impurities and heat attached to the object to be processed is provided near the lower side of the furnace port 41a, which is the outlet.

This gas shower mechanism 90 has a gas introducing pipe 92 connected to an inert gas supply device 49 via a valve 91 and a regulator 73 as shown in FIG. 5, and a gas introducing pipe 92 as shown in FIG. It is connected and fixed to the lower surface of the case 51a of the scavenger 51 via a bracket 93, and the inert gas is directed in a direction (horizontal direction) orthogonal to the inserting / removing direction of the semiconductor wafer 5 by the loading mechanism and over substantially the entire width of the semiconductor wafer 5. It is equipped with a special gas shower nozzle 94 that sprays straightly in a wide thin film shape.

As shown in FIGS. 6 to 8, the gas shower nozzle 94 is mainly composed of a long, wide, and thin hollow flat box-shaped nozzle body 95 bent in an inverted L-shape in vertical section. A connection port (pipe joint) 95 to which the gas introduction pipe 92 is connected at the center of the base end (lower end of the hanging portion) of the nozzle body 95.
and a gas shower outlet 95b at the tip (horizontal end). The entire nozzle body 95 is made of a thin plate made of SUS, and the total length from the base end to the tip is about 360 mm, which is long, and the width dimension is the diameter (total width) of the semiconductor wafer 5 which is the object to be processed. It is as wide as 230 mm and almost as thin as 14 mm.

In this nozzle body 95, FIG. 7 and FIG.
As shown in FIG. 3, the pressure distribution is arranged stepwise from the base end side (lower end side) upward, while the gas flow entering from the gas introduction pipe connection port 95a is diffused / transformed in the width direction of the nozzle main body 95 and the pressure distribution is gradually increased. Plural kinds of baffle plates 96, 97, 98a, 9 to be uniformized
8b, 98c, 98d, 98e, 98f are installed. The first baffle plate 96 has a small semi-circular plate shape facing the connection port 95a. The next baffle plate 97 has a plurality of notches 97a at equal intervals and has a substantially C-shaped plate shape which is arranged over the entire width in the nozzle body 95. The following baffles 98a to 98f are plate-shaped L-shaped sections which are horizontally arranged over the entire width of the nozzle body 95. These baffles 98a to 98f are arranged in zigzag at intervals to form a zigzag gas flow path. There is.

Further, the final baffle plate 98 in the nozzle body 95.
A plurality of straightening vanes 99 are arranged in parallel from the top of f to the tip outlet 95b. These straightening vanes 99 have a structure in which the interior of the nozzle body 95 is partitioned in the width direction and a long landing section 99a is secured between the partitions.

The gas shower nozzle 96 has a long landing distance, and when the wafer boat 61 is inserted into or removed from the process container 41 (load / unload), the N ₂ gas is supplied at 50 to 100 liters / min. In the vicinity of the lower side of the furnace opening 41a of the process vessel 41, a wide thin film-shaped horizontal flow is provided straight from the side, and the ULPA filter 85 is used.
The wind velocity from the horizontal laminar wind (0.75m /
sec) and the semiconductor wafers 5 held in the wafer boat 61 in multiple stages by this N ₂ shower.
Impurities such as O ₂ and hot air are expelled from each other.

The pass box 16 is provided with a gas introduction pipe 101, an injector 102, and an exhaust pipe 103 as a second gas supply / discharge means for replacing the inside of the pass box 16 with an inert gas. The gas introduction pipe 101 is connected to an inert gas supply device 49 via a valve 104 and a regulator 93 as shown in FIG. 5, and its tip is connected to an injector 102 in the pass box 16 from above as shown in FIG. ing. The injector 102 passes the pass box 16
While 50 liter / min of N ₂ gas can be constantly introduced and injected from this one side into the inside, the exhaust pipe 103 is connected to the other side facing this, and this exhaust pipe 103 is connected to the factory exhaust device via the automatic damper 103a. It is connected to 46 so that the gas in the pass box 16 can be constantly exhausted in a state of being flushed.

The injector 102 is a pipe-shaped injector vertically extending from the upper end to the vicinity of the lower end near one side in the pass box 16 and has a large number of small holes vertically formed on the circumferential surface. N ₂ gas is introduced from each of the small holes into the space above the upper and lower transfer stages 18 in the pass box 16 as a horizontal flow from one side. N ₂ gas blowing speed by the injector is 0.75 m / se
c is possible, and the carrier 6 on the transfer stage 18 has a large number of slits on both sides in a state of lying sideways. Therefore, N ₂ gas can flow through the slits inside the carrier 6 through the slits. Through the semiconductor wafer 5 in a direction (horizontal direction) parallel to the main surface of the semiconductor wafer 5 from one side to the other side, and impurities such as O ₂ between the semiconductor wafers 5 are expelled.

Further, as shown in FIG. 5, gas conducting pipes 111 and 112 as oxygen concentration detecting means in the loading area 13 and the pass box 16 are provided,
These are a common oxygen concentration meter (O ₂ sensor) 11
Connected to 3. The oxygen concentration meter 113 has a built-in three-way switching valve and a gas discharge pump, and measures whether the oxygen concentration in the loading area 13 and the pass box 16 is 20 PPm or less.

Further, the controller 1 which receives the signal from the oxygen concentration meter 113 and the signal from the pressure sensor 114 for measuring the atmospheric pressure in the loading area 13.
15 are provided. In response to a control command from the controller 115, the automatic dampers 45a, 54a
a, 72a, 103a and valves 47, 73, 92, 1
04, the front door 20, the automatic doors 31 and 32, the automatic shutter 55, the carrier transfer 22, the transfer machine 63, the boat elevator 62, and other operating units are automatically sequence-controlled.

The operation of the vertical heat treatment apparatus having such a structure will be described. First, since the loading area 13 defined in the apparatus body 1 is relatively narrow, at the time of initial replacement,
The auto-damper 72a of the exhaust pipe 72 as the first gas supply / discharge means is opened, the exhaust gas in the loading area 13 is exhausted by the factory exhaust device 46, and N ₂ gas is supplied from the gas introduction pipe 71 at about 400 liters / min. Introduce. With such a relatively small amount of N ₂ gas supplied, the atmosphere can be easily replaced with the inert gas.

In the stationary state after the replacement, the N ₂ gas introduction amount from the gas introduction pipe 71 is reduced to a small amount of about 50 liters / min, the auto-damper 72a of the exhaust pipe 72 is closed, and the clearance in the loading area 13 is exhausted. Alternatively, a proper positive pressure is applied to the inside of the loading area 13 by the pressure adjusting damper (when the differential pressure between the clean room 2 and the maintenance room 4 is 0.6 to 0.7 mmH ₂ O, it is 0.2 mmH ₂ less than the atmospheric pressure of the clean room _2). N as high as 0.9 mmH ₂ O)
Maintain a ₂ gas atmosphere. The leak gas due to the clearance exhaust is constantly exhausted from the branch pipe 54 with the automatic damper 54a of the heat exhaust pipe 52 of the scavenger 51 to the factory.

On the other hand, the pass box 16 surrounding the transfer stage 18 is always 50 liters / min from the gas introduction pipe 101 as the second gas supply / discharge means through the injector 102.
The N ₂ gas is injected from one side in a horizontal flow and exhausted so as to be pushed out from the exhaust pipe 103 on the other side. By doing so, since the volume inside the pass box 16 is small, the atmosphere is quickly replaced with the inert gas with a very small amount of N ₂ gas supply.

In such a state, first, the front door 20 is automatically opened, and the carrier 6 accommodating a large number of semiconductor wafers 5 from the outside is installed in the loading / unloading area 15 as a left / right posture changing mechanism 21 as an I / O port. Each of them will be loaded and loaded. The posture changing mechanism 21 moves the carrier 6 from the upward position to the position 9
The carrier transfer 22 receives it one after another by turning it 0 degrees and turns it sideways. The carrier transfer 22 raises and lowers it via the elevator 23 and once conveys it to the upper carrier stock stage 24. In this state, the adhered dust such as particles (fine particles) on the main surface of the semiconductor wafer 5 in each carrier 6 is removed by clean air.

After this, at an appropriate timing, the automatic door 31 on the loading / unloading area 15 side of the pass box 16 is opened, and the carrier transfer 22 carries the carrier 6 from the carrier stock stage 24 to the upper and lower parts of the pass box 16. It is carried in on the transfer stage 18 in stages.
At this time, the atmosphere temporarily enters the pass box 16, but after that, the auto door 31 is closed and the pass box 16 is closed.
By making the inside airtight, as described above, the gas introduction pipe 10
The N ₂ gas supplied from the No. 1 through the injector 102 expels the atmosphere in a short time and replaces it with an inert gas.

At this time, the injector 10 of the second gas supply / discharge means
The injector 2, which is No. 2, injects N ₂ gas from a large number of small holes into the space above the upper and lower transfer stages 18 in the pass box 16 from one side as a horizontal flow having a high flow velocity, so that A direction in which the N ₂ gas is parallel to the main surface of the semiconductor wafer 5 (horizontal direction) through a large number of slits on both side surfaces of the carrier 6 lying horizontally on each transfer stage 18 in the pass box 16. Then, the impurities flow out from one side to the other side, and again impurities such as O ₂ between the semiconductor wafers 5 are expelled and removed.

After the inside of the pass box 16 is replaced with the N ₂ gas atmosphere in this way, the automatic door 32 on the side of the loading area 13 is opened, and the inside of the carrier 6 on the upper and lower transfer stages 18 in the pass box 16 is opened. The semiconductor wafers 5 are taken out one by one by the transfer machine 63 and transferred to the wafer boat 61 of the loading mechanism. During this work, the inside of the pass box 16 is replaced with the N ₂ gas atmosphere, so there is no concern that the atmosphere or the like will enter the loading area 13.

The large number of semiconductor wafers 5 transferred to the wafer boat 61 in the loading area 13 are opened by the auto shutter 55, and are raised together with the wafer boat 61 by the boat elevator 62 so that the processing chamber 1
0 is inserted into the process container 41. Then, with the furnace opening 41a closed with the lower flange 61a, the N ₂ gas atmosphere in the process container 41 is exhausted by the exhaust pipe 45, and the process gas is introduced into the process container 41 from the gas introduction pipe 56. The semiconductor wafer 5 is subjected to the required processing by heating the heater 42.

After the processing, the process gas in the process container 41 is exhausted from the exhaust pipe 45, and N ₂ gas is supplied from the gas introduction pipe 56 so that the inside of the process container 41 is the same as the inside of the loading area 13. Replace with ₂ gas atmosphere. Then, the boat elevator 62 descends and the processed semiconductor wafer 5 is pulled back into the loading area 13 together with the wafer boat 61. At that time, the automatic door 32 is opened again, the transfer machine 63 is operated, and the processed semiconductor wafer 5 in the wafer boat 61 is taken out and returned into the carrier 6 on the upper and lower transfer stages 18 in the pass box 16. . Then, the auto door 32 on the loading area 13 side is closed, the opposite auto door 31 is opened, and the carrier transfer 22 is operated to operate the carrier 6
Take out the carrier stock stage 24 once above
Transport to.

After that, the front door 2 of the loading / unloading area 15
0 opens, the carrier transfer 22 starts operating again,
The carriers 6 of the carrier stock stage 24 are successively transferred to the left and right posture changing mechanisms 21, and these are turned 90 degrees to the upward state. With this, the carrier 6 accommodating the processed semiconductor wafer 5 can be taken out to the outside.

By doing so, the atmosphere does not enter into the loading area 13 when the semiconductor wafer 5 is loaded and unloaded, the total amount of inert gas consumed is small, and the cost is saved. In addition, the loading area 13 can be maintained at a positive pressure and a high-purity inert gas atmosphere, and a natural oxide film is generated when the semiconductor wafer 5 is loaded / unloaded into the process container 41, and the semiconductor wafer It is very useful for suppressing the adhesion of impurities to 5 and the chemical reaction.

When the semiconductor wafer processing operation is repeatedly performed, especially, the process container 4 of the wafer boat 61.
When inserting / removing to / from 1 ((load / unload), gaseous impurities such as carbon are generated in the N ₂ gas atmosphere in the loading area 13, and particulate impurities such as oil mist and dust are generated. However, the impurities adhere to the semiconductor wafer or cause a chemical reaction (chemical contamination), which causes deterioration of the characteristics and yield of the semiconductor element, and at the same time, the inside of the process container 41 is opened by opening the furnace opening 41a. Hot air release and high temperature (100
The N ₂ gas atmosphere in the loading area 13 rises abnormally due to radiant heat from the processed semiconductor wafer 5 heated to about 0 ° C.).

From the above, while the clean N ₂ gas as the purge gas is continuously supplied from the gas introduction pipe 71 as described above, the gas circulation cooling and purification system is constantly operated to remove the N ₂ gas in the loading area 13 from impurities. Along with the action of the blower 82, the gas is once conducted to the gas circulation path 81 via the rectifying plate 86, and this is passed through the chemical filter (gas purifier) 83 to the gaseous impurities (moisture, oxygen,
Hydrocarbons and others) are absorbed, and the N ₂ gas is passed through a gas cooler 84 to be cooled to 50 ° C. or lower. Further with filtered trapping particulate impurities N ₂ gas (particle such as dust) by the particle filter 85 of the absolute type of ULPA grade, horizontal laminar flow from one side to the loading area 13 the N ₂ gas It returns to the state by blowing it out.

Now, the N in the loading area 13 is
_{The 2} gas atmosphere is maintained at a high purity and abnormal temperature rise is prevented. Moreover, since N ₂ gas is blown from the filter 85 into the loading area 13 from one side in a horizontal laminar flow (laminar flow) state, even in the loading area 13, the wafer boat 61 is arranged in multiple stages and horizontally. Impurities such as O ₂ between the held large number of semiconductor wafers 5 are expelled and removed.

Further, when the wafer boat 61 is inserted into or removed from (loaded / unloaded from) the process vessel 41, the gas shower mechanism 90 is operated, and N ₂ is passed through the long landing section of the gas shower nozzle 94 on the lower surface of the scavenger 51.
Gas flow is run up, straight to be blown N ₂ gas from the tip blowing port from the side in the lower vicinity of the furnace opening 41a at a high speed in the wide thin film in horizontal flow, on the wafer boat 61 by the N ₂ Shower Impurities such as O ₂ and hot air between the semiconductor wafers 5 which are arranged horizontally in a multistage manner and held horizontally can be reliably driven out. As a result, it becomes possible to further reliably prevent the adhesion of impurities to the semiconductor 5 and the chemical reaction (generation of natural oxide film or the like) on the semiconductor.

Although the processing apparatus of the above-described embodiment is used as an oxidizing apparatus or a CVD apparatus for forming an insulating film on the semiconductor wafer 5 as an object to be processed, the kind of object to be processed and the kind of processing Is not particularly limited,
Of course, it may be a processing device that performs another type of processing. An inert gas other than the above-mentioned N ₂ gas may be supplied depending on the type of these treatments.

[0068]

Since the processing apparatus of the present invention is configured as described above, when an object to be processed is inserted into or removed from the loading area (loading / unloading), the object to be processed is near the insertion / removal port of the processing chamber. Impurities such as O ₂ attached to the object to be processed and heat are expelled so as to be blown out, which is very useful for suppressing adhesion of impurities to the object to be processed and chemical reaction (generation of natural oxide film, etc.). The processing performance of objects can be improved.

Further, the gas shower nozzle of the present invention is particularly effective for use in the gas shower mechanism of the processing apparatus, and is attached to the object to be processed when the object is inserted into and removed from the processing chamber from the loading area. Ensures that impurities such as O ₂ and heat are blown off.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a vertical heat treatment apparatus according to an embodiment of a treatment apparatus of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

FIG. 3 is a cross-sectional view of the device.

FIG. 4 is a sectional view taken along the line BB of FIG.

FIG. 5 is a schematic diagram showing a control system.

FIG. 6 is a plan view of a gas shower nozzle.

FIG. 7 is a front view of the gas shower nozzle.

FIG. 8 is a vertical sectional view of a gas shower nozzle.

[Explanation of symbols]

1 ... Device body, 5 ... Object to be processed (semiconductor wafer), 10 ...
Processing chamber (41 ... Process container), 13 ... Loading area, 41 ... Inserting / removing port (furnace port), 61, 62 ... Loading mechanism (61 ... Wafer boat, 62 ... Boat elevator), 90 ... Gas shower mechanism, 92 ... Gas Introductory pipe, 9
4 ... Gas shower nozzle, 95 ... Nozzle body, 95a ...
Gas inlet pipe connection port, 95b ... Gas outlet port, 96, 9
7,98a-98f ... Baffle plate.

Claims (3)

[Claims] 1. A processing apparatus having a loading area in which a loading mechanism for inserting and removing the object to be processed is installed in a processing chamber for performing a predetermined process on the object to be processed, wherein the loading area is an inert atmosphere. And
When the object to be processed is inserted into or removed from the processing chamber by the loading mechanism from this loading area, an inert gas is injected at a high wind speed in the vicinity of the object insertion / extraction opening of the processing chamber,
A processing apparatus provided with a gas shower mechanism for blowing away impurities and heat attached to the object to be processed. 2. The gas shower mechanism includes a gas introduction pipe for introducing an inert gas and a gas shower nozzle connected to the tip of the gas introduction pipe, and the inert gas is discharged from the gas shower nozzle by the loading mechanism. 2. The processing apparatus according to claim 1, wherein the processing device is configured to inject straightly in a wide thin film shape in a direction orthogonal to the insertion / removal direction of the object and over substantially the entire width of the object to be processed. 3. A long, wide and thin hollow flat box-shaped nozzle body having a gas inlet pipe connection port at its base end and a gas shower outlet at its tip, and a base end in this nozzle body. A plurality of kinds of baffle plates which are arranged in order from the side and which make the pressure distribution uniform stepwise while diffusing and changing the gas flow entering from the gas introduction pipe connection port in the width direction of the nozzle body, Equipped with a plurality of straightening vanes that are arranged in parallel from the final baffle plate to the tip outlet, the gas flow is accelerated in the long landing section between each of these straightening vanes, and goes straight to a wide thin film from the tip outlet. A gas shower nozzle characterized in that the gas shower nozzle is configured to blow it out.